<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8" />
    <title>React 实例</title>
    <script src="https://cdn.staticfile.org/react/16.4.0/umd/react.development.js"></script>
    <script src="https://cdn.staticfile.org/react-dom/16.4.0/umd/react-dom.development.js"></script>
    <script src="https://cdn.staticfile.org/babel-standalone/6.26.0/babel.min.js"></script>
</head>
<body>

<div id="example"></div>
<script type="text/babel">
    class Toggle extends React.Component {
        constructor(props) {
            super(props);
            this.state = {isToggleOn: true};

            // 这边绑定是必要的，这样 `this` 才能在回调函数中使用
            this.handleClick = this.handleClick.bind(this);
        }

        handleClick() {
            this.setState(prevState => ({
                isToggleOn: !prevState.isToggleOn
            }));
        }

        render() {
            return (
                    <button onClick={this.handleClick}>
            {this.state.isToggleOn ? 'ON' : 'OFF'}
        </button>
        );
        }
    }

    ReactDOM.render(
    <Toggle />,
            document.getElementById('example')
    );
</script>

</body>
</html>